Aspirator



Dec. 4, 1928.

E. w. WESCOTT AS PIRATOR Filed Jan. 25, 1927 jfuuerblar Erna/aim W391: It

5? 4Wdag m Ma/ 0 efili 19;?-

Patented Dec. 4, 1928.

UNITED STATES PATENT OFFICE.

ERNEST W. WESGOTT, OF NIA GARA FALLS, NEW YORK, .ASSIGNOR, BY ASSIGN- MENTS, TO STATOR REFRIGERATION, INC., .A. CORPORATION OF DELAWARE.

ASPIRA'IOR.

' Application filed January 25, 1927. Serial No. 163,372.

This invention relates to an improved type of aspirator which may be applied to a wide variety of uses, butis more particularly intended for refrigerating apparatus of the 5 type disclosed by the copendingapplication of Eastman A. WVeaver, No. 733,699, filed August 23, 1924, or the copending applications of Lyman Whitney, Serial Nos. 159,342; 159,343; 159,344; 159,345; and 159,346, filed on even date herewith.

An aspirator of this type is adapted to permit propellent fluid, under comparatively high pressure and temperature, suddenly to expand so that its temperature and pressure 16 are both materially reduced and it is given considerable velocity and kinetic energy. At this point a supply of fluid to be propelled, as for example a refrigerant, is entrained in the current of moving propellent fluid and the mixture is directed through a suitable compression duct or funnel. An aspirator of this character should have poor heat conductivity between the hot portion of the system or the region where the propellent fluid is at a high temperature and pressure and the part of the system wherein its temperature and pressure are materially lower. This is particularly advantageous in refrigerating systems wherein it is undesirable to raise the temperature of the refrigerant at any part of the cycle any further than necessary to impart the required energy thereto; In addition to "obtaining a high efliciency of vapor flow in an aspirator of this type and the smallest frictional losses which are commensurate with the mechanical mixture which must take place i at the outlet of the aspirator nozzle, it is also desirable to provide means whereby the nozzle may be readily and accurately centered in relation to the compression duct or funnel.

A further aspect of the invention relates to a novel indicator located exteriorly of the apparatus to show whether or not the aspi-. rator nozzle is in its proper aligned position and, if for any reason the aspirator is moved out of alignment, to facilitate its return to its proper aligned position without necessitating disassembling the apparatus.

The present invention pertains more parhead for the mixing or head-chamber of the aspirator and the combination of such a head with the aspirator nozzle in a manner to provide the above and further advantages which will become apparent to those skilled in the ticularly to the provision of an improved art upon a reading of the subjoined description and claims in conjunction with the accompanying drawings, in which:

Fig, 1 is a central longitudinal cross sectionof one form of aspirator adapted to receive propellent fluid of comparatively high density;

Fig. 2 is an elevational detail of improved indicating means to assist in keeping the aspirator assembly in proper alignment; and

Fig. 3 is a section on line '3-3 of Fig. 2.

An aspirator of the type disclosed in the accompanying drawing may preferably be connected to a' source of high pressure and high temperature propellent fluid by a duct 17, which may terminate in a suitable high pressure chamber or reservoir 2 at the inlet of the aspirator nozzle 3. Thenozzle may be of suitable Venturi form so that the propellent fluid or vapor may expand approximately adiabatically, its pressure being decidedly reduced, its temperature falling abruptly, and its velocity and kinetic energy increasing as it enters mixing chamber 4. Vapor or, gas which is to be propelled may be introduced to mixing chamber 4 by a vapor duct 5. Preferably the, aspirator nozzle projects somewhat beyond the inner wall of the mixing chamber head 4 in order more efi'ectively to entrain vapor from the mixing chamber in the path of the rapidly moving propellent particles or molecules and thus more efficiently to compress the propelled vapor.

In concentric alignment with the 'et 3 is the compression funnel 14 which may ave an outwardly flared inlet, as shown,,and which is adapted to receive the rapidly moving mixture and guide it through an elongate intermediate passage where the propellent fluid may be condensed; means for this purpose being illustrated in the water jacket-15, with supply and outlet ducts 10 and 11 respectively. Preferably the compression funnel 14 projects into the mixing chamber 4 for a considerable extent so that the space between the inner end of the jet 3 and the adjoining end of the funnel 14 may be considerably less than distortion or'diaphragm action,but so that in its crowned form it may be relatively stifi and may hold the aspirator jet 3 in proper concentric alignment with fumiel 14, althoughstill permitting limited movement of the nozzle, for instance by application of suitable force upon the chamber 2, in order to effect the accurate alignment of the nozzle and funnel. The crowned head of the mixing chamber may be advantageously formed of an alloy of nickel and chromium, such as a nickel chromium steel or the material commonly tivel thin material of the crown or head 7, a

suita le expansiblecoupling 12 may be located in the duct 2 as described more particularly in thesaid copending application.

The thinness of the chamber head, combined with the length of the metal path through which heat must be conducted and the tendency of the alloy itself to provide ineflicient heat conduction, reduces the heat conductivity between the hot, high pressure chamber 2 and the comparatively cool head chamber 4 to the minimum which is conform able with suitable mechanical strength for this portion of the aspirator, at the same time permitting centering of the nozzle in accurate alignment with the compression duct or funnel.

Since the head 7 of the mixing chamber as well as the aspirator nozzle 3 may be of comparatively thin metal which may be accidentally bent or twisted so that the nozzle is moved out of accurate alignment with the compression funnel 14, it is desirable to provide means exteriorly arranged upon the apparatus to indicate whether or not the nozzle is in its proper accurately aligned position. For this purpose indicator element 70 preferably is secured to the high pressure chamber 2 in order to project upwardly in alignment with the central longitudinal axis of the nozzle 3, while U-shaped bracket has its legs symmetrically secured to opposite sides of the mixing chamber 4 (Fig. 2) this bracket has its bight portion provided with a bolt 66 which is adapted to clamp a plate 67 thereto. Plate 67 is provided with an enlarged opening 68 adapted to receive the bolt and to permit its adjustment in relation to bracket 65 being also provided with a depending projection 69, the end of which is adapted to be in close juxtaposition to the end of p,ointer'70 as shown in Figs. 2 and 3 when the nozzle is in its properly aligned relation to the compression funnel. However, if for any reason the nozzle is accidentally moved out of accurate alignment the end of indicator element 70 will be moved out of its normal position close to the end of projection 69.

ince, however, the connection 12 is flexible the pipe 17 may be moved in any suitable manner to return the nozzle 3 and pointer 70 to their normal position.' Obviously the plate 67 is clamped in its proper adjusted position when the machine is initially assembled and nozzle 3 and funnel 14 are originally aligned. Thereafter the plate remains fixed in place and nozzle-3, together with pointer 70, may be returned to proper positioriwithout interference with the interior of the ap paratus. Iclaim: 1. In an aspirator wherein a propellent fluid at ahigh temperature and pressure is adapted to be materially reduced in both pressure and temperature when entering a mixing chamber into which a propelled fluid is drawn, a mixing chamber, a head for said mixlng'chamber of crowned form and of thin slightly distortable material.

2. In an aspirator wherein a propellent fluid at a high temperature and pressure is adapted to be materially reduced in both pressure and temperature when entering a mixing chamber into which a propelled fluid is introduced, a mixing chamber, a headfor said chamber comprising an annulus of crowned form and of relatively thin metal of comparatively low heat conductivity, and a nozzle at the mid portion of the head.

3. In an aspirator wherein a propellent fluid at a high temperature and pressure is adapted to be materially reduced inboth pressure and temperature when entering a mixing chamber into which a propelled fluid is introduced, a, mixing chamber, .a head for tended metal annulus and an aspirator nozzle projecting through the center of the head and into the mixing chamber for a distance beyond the inner surface of the chamber head.

4. In an aspirator wherein a propellent fluid at a high temperature and pressureis adapted to be materially reduced in both pressure andtemperature when entering a mixing chamberinto which a propelled fluid is introduced, a mixing chamber,'.a head for said chamber of sheet material which is normally readily distortable but which is formed into a crowned annular form in order to be comparatively stiff, an aspirator jet projecting through the metal of said head into the mixing chamber and being supported by said head in such a manner that its angular relation to the chamber may be slightly altered due to the limited degree of distortionof the head permitted by the shape and gauge of the metal thereof.

5. In an aspirator wherein a propellent fluid at a high temperature and pressure is adapted to be materially reduced 1n both pressure and temperature when entering aunxing chamber into which a propelled fluid is introduced,.a mixing chamber, a head for said chamber of sheet metal of low heat conductivity, which is normally readily distortable but which is formed into a crowned annular form in order to be comparatively stitf, an aspirator nozzle projecting through the "metal of said head into the mixing chamber head of said chamber, the head comprising a sheet ofmaterial of dlshed tormation to pro- I vide poor heat conductivity between the nozzle and the remainder of the chamber.

7. In apparatus of the class described wherein a, propellent fluid at a high temperature and pressure is adapted to be materially reduced in both pressure and. temperature when entering a mixing chamber into which a propellent fluid is introduced, an aspirator nozzle projected into the mid portion of the head of said chamber, said head comprising a sheet of relatively thin metal of comparatively low heat conductivity, an outlet in the mixing chamber substantially aligned with the aspirator nozzle in its normal position and means located exteriorly of the apparatus for indicating the relative alignment of said nozzle and said outlet.

8. Apparatus'of the class described comprising a duct for supplying prope-llentfluid,

a nozzle connected to said duct, a flexible connection 1nsaid duct, a mixing chamber at the outlet of the nozzle, an outlet for said chamber opposite said nozzle outlet, and means indicating the relative alignment of said nozzle and said last-named outlet.

'9. Apparatus of the class described comprising a .duct for supplying propellent fluid, a nozzle connected -to said duct, a flexible connection in said duct, a mixing chamber at .the outlet of the nozzle, an outlet for said chamber opposite said nozzle outlet, said outlets being normally enc'losed within the apparatus, and adjustable, exteriorly arranged means to indicate the relative position of the .nozzle and mixing-chamber outlet, the .flexible connection permitting movement-of the nozzle into proper relation to the lIllXll'lg chamber'outlet as determined by the indieating means. i I

10. Apparatus of the class described comprising a duct for supplying .propellent fluid, a nozzle connected to said duct, a flexible connection in said duct, a mixing chamber at the outlet of the nozzle, an outlet for said chamber opposite said nozzle outlet, said outlets being normally enclosed within the apparatus, and adjustable, exteriorly arranged means-to indicate the relative position of the nozzle and mixing chamber outlet, the flexible connection permitting movement of the nozzle into proper relation to themixing chamber outlet as determined by the indieating means, said indicating means comprising a bracket fixed to the mixing chamber and an indicating element connected to the nozzle, whereby the relative position of the exteriorly mounted bracket and element indicates the relative position of the nozzle and mixing chamber outlet within the apparatus. Signed by me at Boston, Massachusetts, this 22nd day of January, 1927.

ERNEST wnscorr 

